/**
 * 移除指定对象
 * @param users
 * @param username
 */
public static void removeSpecifiedObject(List<User> users, String username) {
    int size = labels.size();
    for (int i = size - 1; i >= 0; i--) {
        User item = labels.get(i);
        if (item.getUserName().equals(username)) {
            users.remove(username);
        }
    }
}